Effective systems for dispensing or delivery of liquid reagents from containers to sample holders are necessary for the efficient operation of many analytical instruments. Such systems should provide on demand delivery of liquids, be resealable and be reusable. Known systems for such delivery of liquids, such as systems using septums and needles, suffer from certain disadvantages, such as limited resealability and reusability, handling difficulties or septum bleed.
Accordingly, it is the object of this invention to provide a novel liquid delivery system.
It is also an object of this invention to provide a novel liquid delivery system that is resealable and reusable. SUMMARY OF THE INVENTION
This invention relates to a liquid delivery system positioned below the level of the liquid in a container, comprising:
(a) a seal assembly comprising an upper elastomeric member in contact with the liquid in a container, having at least one liquid passage vent and at least one air passage vent separate from the liquid passage vent; a seating member disposed below the upper elastomeric member which is configured to receive a dispensing probe, thereby allowing communication between the dispensing probe and the upper elastomeric member and in the absence of a dispensing probe, to reversibly seal the liquid passage vent; means for preventing the liquid from entering the air passage vent; and means for reversible retention of a dispensing probe within the seal assembly; and
(b) a dispensing probe having at least one air inlet and at least one liquid outlet separate from the air inlet, which dispensing probe is capable of insertion into and reversible retention within the seal assembly, wherein insertion of the dispensing probe into the seal assembly causes the upper elastomeric member to flex away from the seating member, thereby opening the liquid passage vent, establishing communication between the liquid passage vent and the liquid outlet, and allowing the liquid to flow from the container through the liquid passage vent into the liquid outlet; and also establishes communication between the air inlet and the air passage vent, thereby allowing air to flow through the air inlet and the air passage vent into the container to replace the liquid which has flowed from the container; and wherein removal of the inserted dispensing probe from the seal assembly causes the upper elastomeric member to resume contact with the seating member, thereby sealing the liquid passage vent, and preventing liquid flow.